The present invention relates generally to a fluid level regulator. More particularly, the present invention relates to an oil level regulator for controlling the oil level in a compressor crankcase.
Mechanical oil level control systems and regulators are generally known for controlling the oil level in a compressor crankcase. For example, U.S. Pat. No. 2,246,244 discloses a prior oil level control system for a refrigeration compressor. An oil level regulator is desirably capable of adjusting the oil level of the associated crankcase within predetermined oil level limits. The oil level regulator disclosed in the aforementioned patent is not adjustable.
Adjustable mechanical regulators are generally known. U.S. Pat. No. 4,428,208, incorporated herein in its entirety, relates to such a device. That device includes a float which is connected at its side to a pivotable lever. Responsive to the oil level, the float travels along an arc, the float motion being constrained by the attached lever. The lever is operable to open or close a valve to control a flow of oil through an inlet. The inlet includes a vertically adjustable position to which the valve, lever and float assembly are attached. This assembly is adjustable with a separate adjustment pin which extends vertically through the top of the regulator housing to the valve. The pin is threaded to the valve so that the rotation of the pin from outside the regulator causes vertical adjustment of the valve assembly. Because the float has an amount of horizontal travel along its arc, the width of the conventional regulator must be sized accordingly. Therefore, a regulator design is desirable which is compact and simple to adjust.
An oil level regulator is disclosed in U.S. Pat. No. 5,542,499, incorporated herein in its entirety, for controlling the oil level in the crankcase of one or more refrigeration compressors or the like. The regulator has a closed chamber for containing the oil. A float-controlled switch is operable to actuate a solenoid valve for introducing liquid into the chamber as necessary to maintain the oil level in the chamber and the compressor crankcases. The regulator actuates an indicator, such as a light or an audible alarm, when a low-oil condition is present. Also, the regulator terminates operation of the compressor at a critically low oil level in order to prevent damage from inadequate lubrication.
These types of regulators include no time delay or controlled feed cycle. In some instances, too much oil or too little oil may be fed to a crankcase under varying operation conditions. In other cases, the introduction of high pressure oil may cause the float switch to bounce causing abbreviated feed cycles of a fraction of a second or false alarms. This lack of a feed cycle renders such regulators poorly suited to high-pressure oil systems. Additionally, many of these prior art regulators include 24-volt power systems which require a customer to supply relay and time delay features to open the compressor control circuit and shut off the compressor. Further, such regulators reset immediately upon the oil level in the compressor reaching a set point. Such designs allow the compressor to run without correcting the initial oil level problem or cause.